Engine starting device



Oct. 26, 1943. J. E. BUXTON ENGINE STARTING DEVICES Filed July 2, 1942 R O m w m m 1 a 1 M 0/0 I m a s. U W 95 7 pH J W W I m 1H. n W36 a I r b I. E

Patented Oct. 26, 1943 PATENT: mm

James E. Bnxton, Elmira, N.'Y., assignor to Bendix Aviation Corporation poration of Delaware 1 Application July 2, 1942, Serial No. 449,410

Claims;

The present invention relates to engine starting devices and more particularly to a device for assuring the; engagement of a drive pinion with its engine gear, and maintaining such engagement until the engine is reliably self-operative.

In engine starter drives of the type in which a pinion is automatically traversed into and out of. engagement with an engine gear, various forms of detent have been .used to .ensure traversal of the pinion into mesh when the power shaft is rotated. Furthermore, in .those drives of this type which are arranged to hold the pinion in mesh until the engine is reliably selfopera'tive, various forms of latch have been used tofprevent premature de-mesh of the pinion.

It is an object of the present invention to provide a novel engine starter drive incorporating unitary means for ensuring traversal of the pinion into mesh and for thereafter holding the pinion in mesh.

It is another object, to provide such a device incorporating an overrunning clutch connection to the pinion to prevent rotating the starting motor from the engine when the engine starts.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing, in which:

Fig. 1 is a side elevation partly in section of a preferred embodiment of the invention show ing the parts in idle position;

Fig. 2. is a similar view showing the parts in cranking position, and including, a diagrammatic showing of a starting system incorporating the invention; and i Fig. 3 is a section taken substantially on the line 3-3 of Fig. 2 showing the overrunm'ng clutch driving connection to the pinion.

e In Fig. 1 of the drawing there is illustrated a power shaft I having a screw shaft 2 journalled thereon and yieldably connected to rotate therewith by means of a drive spring 3 anchored to the drive shaft at 4 and to the screw shaft at 5. A nut 6 is threaded on the screw shaft and has journalled thereon a pinion 'l which is connected for rotation with the nut by means of an overrunning clutch indicated generally by numeral 8. Traversal of the nut 6 on the screw shaft 2 causes the pinion 1 to be carried into and out of mesh with a member such as a gear 9 of an engine to be started, the operative position of the pinion being defined by a stop nut H on the screw shaft and a thrust collar l2 slidably mounted on a smooth portion I 3 of the screw shaft. An anti-drift spring [4 is interposed be-,

, South Bend, Indqa cortween the thrust collar 12 andstopnut .1 land serves to normally maintain th'e pinionin idle position. 1

According to the present invention means are. provided for ensuringv traversal of the pinion: into mesh with the engine gear upon rotation of the screw shaft and for thereafter holding the pinion in mesh. As here shown, this meansis in the form of a detent l5 slidably mounted in a fixed. bearing member It. in position to engage. between the teethof the pinion I and oppose rotation thereof during the meshing. movement, and to drop down behind thepinion and act as a latch to hold the pinion meshed with the engine gear.

This, detent may be operated manually or by means of any suitable actuating mechanism. One formof actuating mechanism for the pinion detent is shown in Fig. l, where the bearing member I6 is in the form of a cylinder, and the detent I5 is formed with a piston head l5a slidably fitting the cylinder. Aspring [5b normally presses the detent against the pinion I, and a connection I is provided from the upper end of the cylinder to the intake manifold of the 1 If the engine then dies, the starter will resume cranking, and when the engine runs, the intake vacuum so generated withdraws the detent and permits the pinion to return to idle position.

Anelectrical arrangement for actuating the detent is illustrated diagrammatically in Fig. 2 which shows a starting circuit including a starting motor i1 connected through a starting switch l8 to a battery l9. A detent actuating solenoid 2| is connected in series with the starting motor so as to be energized concurrently therewith by closure of the starting switch, the cranking and detent circuit being completed through the ground connections 22 and 23. In this case the detent is normally held disengaged from the pinion by a spring 20. e

In the operation of this form of the invention closure of the starting switch l8 causes energization of the starting motor I! and of the solenoid 2| whereby the screw shaft 2 is caused to rotate and at the same time the detent I5 is pressed against the pinion 'l by the solenoid 2| to prevent rotation thereof. The consequent translation of the pinion into mesh with the engine I gear 9 causes the pinion to move away from the detent, allowing the detent to drop down behind the pinion as shown in Fig. 2 when the pinion ted by the overrunning clutch 8, while thepinion is held in mesh by the detent l5. Ii: the

engine should fail to continue self-operative,

cranking will immediately be resumed until a successful start is secured. When the engine is reliably self-operative the operator opens the starting switch i8 whereupon the detent I5 is disengaged from the pinion by the spring 20, and the pinion is threaded back to its idle position.

Although certain embodiments of the invention have been shown and described in detail, it will be understood that other embodiments are possible and that various changes may be-made in'the design and arrangement of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. In an engine starter drive a screw shaft, a nut threaded thereon, a'pinion connected to the nut for longitudinal movement therewith into and out of engagement with a gear of an engine to be started, an overrunning clutch connection between the nut and pinion, detent means for resisting rotation of the pinion when in idle position to ensure its traversal into mesh on rotation of the screw shaft, and means for moving said detent when the pinion is in mesh with the engine gear, into position to prevent disengagement of the pinion from the engine gear.

2. In an engine starter drive a screw shaft, a nut threaded thereon, a pinion connected to the nut for longitudinal movement therewith into and out of engagement with a gear of an engine to be started, an overrunning clutch connection between the nut and pinion, a detent, and means for moving the detent into engagement with the pinion to resist its rotation and thereby ensure its traversal into operative position when the screw shaft is rotated, said detent being arranged to drop back of the pinion when fully meshed with the engine gear and prevent the pinion from dis-engaging the engine gear.

3, In an engine starter drive a screw shaft, a nut threaded thereon, a pinion swiveled on the nut and moveable thereby into and out of engagement with a gear of an engine to be started, an overrunning clutch between the nut and pinion, a detent, and means for moving the detent to engage the periphery of the pinion and resist its rotation when in idle position, said detent being arranged to drop down back of the pinion when it is fully meshed with the engine gear, tohold the pinion in mesh.

4. In an engine starter drive as set forth in claim 3, means responsive to self-operation of the engine for withdrawing the latch from its holding position.

5. In an engine starter drive as set forth in claim 3, means responsive to closure of the starting switch for moving the detent into engagement with the pinion, and means for withdrawing the detent when the starting switch is opened.

JAMES E. BUXTON. 

